tty_io: check return code of tty_register_device

Function tty_register_device may return ERR_PTR(...). Check for it.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 22 insertions, 2 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index d6c659f2f659..e185db36f8ad 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -3004,6 +3004,7 @@ int tty_register_driver(struct tty_driver *driver)
         int i;
         dev_t dev;
         void **p = NULL;
+        struct device *d;
 
         if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
                 p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL);
@@ -3051,12 +3052,31 @@ int tty_register_driver(struct tty_driver *driver)
         mutex_unlock(&tty_mutex);
 
         if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) {
-                for (i = 0; i < driver->num; i++)
-                    tty_register_device(driver, i, NULL);
+                for (i = 0; i < driver->num; i++) {
+                        d = tty_register_device(driver, i, NULL);
+                        if (IS_ERR(d)) {
+                                error = PTR_ERR(d);
+                                goto err;
+                        }
+                }
         }
         proc_tty_register_driver(driver);
         driver->flags |= TTY_DRIVER_INSTALLED;
         return 0;
+
+err:
+        for (i--; i >= 0; i--)
+                tty_unregister_device(driver, i);
+
+        mutex_lock(&tty_mutex);
+        list_del(&driver->tty_drivers);
+        mutex_unlock(&tty_mutex);
+
+        unregister_chrdev_region(dev, driver->num);
+        driver->ttys = NULL;
+        driver->termios = NULL;
+        kfree(p);
+        return error;
 }
 
 EXPORT_SYMBOL(tty_register_driver);